An inherent problem in the melt processing of certain polymers, such as poly(vinyl chloride) (PVC), is that it tends to stick to hot metal surfaces. When sticking occurs, it causes the processing line (e.g, milling, molding) to be shut down and cleaned before it can be used again. With no lubrication, sticking may occur within minutes or hours. Therefore, lubricants are used, typically at very low loading levels, but these low levels do provide lubrication and release of the polymer from the hot metal surfaces. Small molecule as well as polymeric lubricants are often used separately or together, and both have their strengths and weaknesses. One feature of such lubricants is efficiency, which relates to a critical loading level above which no further lubrication effect is observed.
Despite known lubricants, there still exists a need for higher efficiency lubricants to prevent sticking on hot metal surfaces.